Use of Autoland in Adverse Weather
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Use of Autoland in Adverse Weather
Dear Experienced Pilots
I have a query. If on an ILS, landing in Cat 1 conditions with heavy rain with Cat 2 Dual on FMA, if visibility, despite using wipers/rain repellent, drops suddenly at MDA for a very short period (just for a few critical seconds) without losing the lights but they become fuzzy and may not guarantee a good flare and touchdown, would you continue the approach without disconnecting the autopilot and carry out an autoland, go around, or disconnect autopilot and do a manual landing? I take into consideration a busy airport wherein if I was to do a GA, it would involve a large fuel loss. Of course safety is the primary issue as always. Thank you ladies and gentlemen for your response.
I have a query. If on an ILS, landing in Cat 1 conditions with heavy rain with Cat 2 Dual on FMA, if visibility, despite using wipers/rain repellent, drops suddenly at MDA for a very short period (just for a few critical seconds) without losing the lights but they become fuzzy and may not guarantee a good flare and touchdown, would you continue the approach without disconnecting the autopilot and carry out an autoland, go around, or disconnect autopilot and do a manual landing? I take into consideration a busy airport wherein if I was to do a GA, it would involve a large fuel loss. Of course safety is the primary issue as always. Thank you ladies and gentlemen for your response.
Last edited by agada; 19th Oct 2012 at 09:07.
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in my company if you want to do an autoland you have to engage the second autopilot way before the mda
so in your case it will be a go around
so in your case it will be a go around
Mate, if you haven't planned and briefed an auto land, don't do an auto land. Stick to what you have briefed you will do . If you have to go around then good stuff, you've gained the experience of one more G/A and and in doing so you've maintained a safe environment for all those people sitting behind you.
Changing your plan at the last second is a bad idea.
Changing your plan at the last second is a bad idea.
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Many companies in EU-land preach the use of dual autopilots on all ILS approaches, so yes, you could find yourself technically able to autoland from DA/H. However, this except in an extreme emergency, is not allowed and worries about 'a large fuel loss' do not normally constitute an emergency. Loss of visual reference at DA/H requires a G/A and I am surprised from your 'profile' that you need to ask!
Your description 'without losing the lights' does not actually constitute loss of visual reference in EUOPS and a 'drop' in visibility past the relevant point does not count - it is the crew's decision whether to continue.
I note you do not tell us which regulatory framework you are licensed under, so it may, of course, be 'acceptable' in yours.
Your description 'without losing the lights' does not actually constitute loss of visual reference in EUOPS and a 'drop' in visibility past the relevant point does not count - it is the crew's decision whether to continue.
I note you do not tell us which regulatory framework you are licensed under, so it may, of course, be 'acceptable' in yours.
Go around. If you attempt to fly below your briefed da you're asking for trouble. If at planned da you lose the required visual references, or if in your judgement you can't see well enough to continue safely you must go around. In the time it takes to go from 200 ft agl (cat 1) to 100 ft agl (cat 2) you don't have time to consider variables such as
1) are LVP's in force
2) aircraft auto land serviceability
3) airfield auto land capability
4) auto land crosswind limits
5) decide on and re bug a new minima
There are other things to consider, that list is just a snapshot. Far safer to go around, re brief, and try again. No one has ever collided with the sky.
1) are LVP's in force
2) aircraft auto land serviceability
3) airfield auto land capability
4) auto land crosswind limits
5) decide on and re bug a new minima
There are other things to consider, that list is just a snapshot. Far safer to go around, re brief, and try again. No one has ever collided with the sky.
Last edited by Locked door; 19th Oct 2012 at 09:39.
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Autoland systems are basically designed to be used during low visibility caused by phenomena like fog, NOT for tropical downpours with or without windy conditions. Foggy conditions hardly ever go together with extreme wind conditions. (excluding Scotland... 
)
Autopilots most likely have insufficient authority to cope with a large and sudden wind shear or down draft because of entering a shower on short final or flare heights.
Loosing visual reference AFTER You made the decision to land is a nasty one. I one time asked our training manager to incorporate that item in a new Type recurrent. He did and it made for some interesting experiences with several crews as I heard later.
)Autopilots most likely have insufficient authority to cope with a large and sudden wind shear or down draft because of entering a shower on short final or flare heights.
Loosing visual reference AFTER You made the decision to land is a nasty one. I one time asked our training manager to incorporate that item in a new Type recurrent. He did and it made for some interesting experiences with several crews as I heard later.
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Technically he would not need more than one autopilot engaged to perform an autoland if he was sitting in a 737.
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"Autoland systems are basically designed to be used during low visibility caused by phenomena like fog, NOT for tropical downpours with or without windy conditions"
I can remember an autoland approach to LHR when it was heaving it down with quite a strong, gusting wind as well
Went off quite well - better than hand flying for sure
I can remember an autoland approach to LHR when it was heaving it down with quite a strong, gusting wind as well
Went off quite well - better than hand flying for sure
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On the bus we fly all our ILS's with both auto pilots in so Cat 3 Dual is always annunciated irrespective of whether it is a Cat 1 or Cat 2/3 auto land (Cat 2 is always auto land for us). Clearly on a Cat 1 approach we would disconnect and land manually.
If you have planned a Cat 1 approach then that is what you fly. If you achieve the required references by DA then you can continue to land. If you do not achieve those references, or lose them below DA then you go around. It is that simple.
To do otherwise would be fool hardy in the extreme as the airfield will not be safeguarded, you will be busting your briefed minima and will not have pre briefed what you are up to.
Now if you are in some kind of dire emergency then that would be different but it would need to be dire.
If you have planned a Cat 1 approach then that is what you fly. If you achieve the required references by DA then you can continue to land. If you do not achieve those references, or lose them below DA then you go around. It is that simple.
To do otherwise would be fool hardy in the extreme as the airfield will not be safeguarded, you will be busting your briefed minima and will not have pre briefed what you are up to.
Now if you are in some kind of dire emergency then that would be different but it would need to be dire.
Controversial, moi?
Autoland systems are basically designed to be used during low visibility caused by phenomena like fog, NOT for tropical downpours with or without windy conditions. Foggy conditions hardly ever go together with extreme wind conditions. (excluding Scotland... )
Autopilots most likely have insufficient authority to cope with a large and sudden wind shear or down draft because of entering a shower on short final or flare heights.
Autopilots most likely have insufficient authority to cope with a large and sudden wind shear or down draft because of entering a shower on short final or flare heights.
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Surely you would have anticipated such conditions and set-up for an autoland?
Personally I brief autoland if any significant cloud below 500ft or vis less than 1500m and consider reverting to Cat I if appropriate. Can't go the other way though, and its a bit embarrassing to explain to the CP why you had to go around in a CatIII equipped aeroplane just because you hadn't set it up...
Boeing 737 & 1 autopilot. "technically"... Hmmm, well, yes, it will autoland fine with just one but there's no redundancy so not exactly a sensible thing to do unless you're going to die otherwise. You "could technically" do all sorts of things in any aeroplane but that's a pretty pointless line of discussion really.
Personally I brief autoland if any significant cloud below 500ft or vis less than 1500m and consider reverting to Cat I if appropriate. Can't go the other way though, and its a bit embarrassing to explain to the CP why you had to go around in a CatIII equipped aeroplane just because you hadn't set it up...
Boeing 737 & 1 autopilot. "technically"... Hmmm, well, yes, it will autoland fine with just one but there's no redundancy so not exactly a sensible thing to do unless you're going to die otherwise. You "could technically" do all sorts of things in any aeroplane but that's a pretty pointless line of discussion really.